I should’ve noted this earlier but forgot: Redlers released Mellel 2.7 in mid-September. The biggest new feature from my perspective is Snow Leopard compatibility.
Quick background: Mellel is a word processor for OS X, and Redlers has listed the top ten reasons to switch (presumably from Word) at the link. Many academics use Mellel for its stability, language support, and excellent formatting, and I sometimes use it for very long documents because it doesn’t crash easily. The major problem: no track changes/editing support. But recent forum activity indicates that track changes might be in development; you can see my own comments in the thread.